Occurs when the origin web server refuses connections from Cloudflare. Security solutions at your origin may block legitimate connections from certain Cloudflare IP addresses. The most common ones are:
- Offline origin web server application
- Blocked Cloudflare requests
Step 1: Contact NET Support
Contact your site administrator or NET Support to eliminate these common causes:
- Ensure your origin web server is responsive
- Review origin web server error logs to identify web server application crashes or outages.
- Confirm Cloudflare IP addresses are not blocked or rate limited
- Whitelist all Cloudflare IP ranges in your origin web server’s firewall or other security software
- Find additional troubleshooting information on the Cloudflare Community.